Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual foi a população de 2006 para a área do governo local do conselho de Alexandrina cujo ranking era menor que 19?
 ###Tabelas: CREATE TABLE 2006_ladder (2006_ladder_id AUTO_INCREMENT PRIMARY KEY, Golden Rivers VARCHAR, Wins INT, Byes INT, Losses INT, Draws INT, Against INT) CREATE TABLE crime_statistics:_1995_2011_non-homicide (crime_statistics:_1995_2011_non-homicide_id AUTO_INCREMENT PRIMARY KEY, Year INT, Population INT, Total INT, Violent INT, Property Crimes INT, Forcible rape INT, Robbery INT, Aggravated assault INT, Burglary INT, Larceny Theft INT, Vehicle Theft INT) CREATE TABLE 25_largest_local_government_areas_by_population (25_largest_local_government_areas_by_population_id AUTO_INCREMENT PRIMARY KEY, Rank INT, Local government area VARCHAR, Population 2006 census INT, Population 2007 estimate INT, Growth rate VARCHAR, Stat. division/district VARCHAR) CREATE TABLE head-to-head_records_against_other_countries (head-to-head_records_against_other_countries_id AUTO_INCREMENT PRIMARY KEY, Games INT, Wins INT, Draws INT, Losses INT, Goals For INT, Goals Against INT, Goal Differential VARCHAR) CREATE TABLE affiliates (affiliates_id AUTO_INCREMENT PRIMARY KEY, Calls VARCHAR, Frequency VARCHAR, Branding VARCHAR, Format VARCHAR, Timeslot VARCHAR, Group owner VARCHAR)  
SELECT AVG Population 2006 census FROM 25_largest_local_government_areas_by_population WHERE Local government area = alexandrina council AND Rank < 19